terradart_hcl

A pure Dart front-end for Terraform configurations: an HCL native-syntax parser, a *.tf.json decoder, and a shared module model (TfModule) that both produce. It is the input side of terradart migrate (the HCL → Dart migrator, #80) and depends on no other TerraDart package.

What it does

• Lossless structure. Block bodies are ordered lists of entries, so repeated blocks (container {} ×2, env {} ×3, lifecycle_rule {} ×2) survive exactly as written. Every node carries a SourceRange, and comments are kept on the entry they precede, so a caller can copy any block back out verbatim.
• Shallow expressions. Literals, tuples, objects, traversals (google_pubsub_topic.t.name, var.x, local.y[0]) and templates ("${var.a}-x", heredocs) are parsed exactly. Everything else — function calls, operators, conditionals, for, splats — is kept as RawExpr with its verbatim source and balanced brackets. Migration needs classification, not evaluation, so the full HCL expression grammar is deliberately not implemented.
• Two front-ends, one model. parseHcl and decodeTfJson both yield an HclFile; TfModule.fromFiles reads the Terraform structure (terraform settings, providers, variables, locals, outputs, resources, data sources, module calls, and moved / import / check / removed kept opaque) from either.
• Serializer. HclWriter renders a file or expression back to HCL; parse → write → parse is structurally identical.

Usage

import 'package:terradart_hcl/terradart_hcl.dart';

void describe(String source) {
  final file = parseHcl(source, fileName: 'main.tf');
  for (final block in file.body.blocksOf('resource')) {
    print('${block.labels[0].text}.${block.labels[1].text}');
  }

  final module = TfModule.fromFiles([file]);
  for (final r in module.resources) {
    final name = r.body.attribute('name')?.value; // an Expr
    print('${r.type}.${r.name}: ${name is LiteralExpr ? name.value : name}');
  }
}

Conformance

test/specsuite_test.dart runs every case of the hashicorp/hcl specsuite through the parser: cases the suite expects to succeed must parse, and the heredoc / literal cases are checked against the suite's expected values. The suite is fetched with a shallow git clone into .dart_tool/hcl_specsuite on first run (it is not vendored); set TERRADART_HCL_SPECSUITE to point at an existing checkout, or TERRADART_HCL_SPECSUITE_SKIP=1 to skip the test offline.

Status

Alpha, like the rest of TerraDart. Published to pub.dev in lockstep with the other packages.